Patent GB-683803-A (GB)
Title: Improvements in or relating to the manufacture of complex esters
Inventor: MORTON RONALD WILLIAM
IPC: C07C69/34
Filed: 1949-03-17
Abstract: Complex esters having the general formula R1-OOC-R2-COO-R3-OOC-R4-COOR5 in which R1 and R5 are aliphatic alcohol or ether-alcohol residues, R2 and R4 are the hydrocarbon radicals of aliphatic dicarboxylic acids or are direct carbon-to-carbon linkages and R3 is the hydrocarbon or oxygenated hydrocarbon radical of a glycol or polyglycol, all the R's being saturated, are prepared by heating together in proportions yielding the complex ester, the appropriate diester of the alcohol and dicarboxylic acid with the glycol or polyglycol in the presence of an esterification catalyst and removing the alcohol of esterification formed.  The complex esters preferably contain 20-100 carbon atoms per molecule.  The esters may be used as lubricants.  Suitable starting materials are C4 to C24 polyglycols, C1 to C12 alcohols, especially 2-ethyl hexanol and iso-octanol and C6 to C20 dicarboxylic acids, especially adipic and sebacic acids, though acids down to oxalic may be used.  Experiments are described illustrating the production of complex esters from di-2-ethylhexyl sebacate and (1) triethylene glycol and (2) polyglycol 200 (predominantly tetraethylene glycol) by refluxing the reactants in presence of p-toluene sulphonic acid and removing the alcohol of esterification as overhead and comparison is made with the methods of making the same triethylene glycol complex ester by reacting together triethylene glycol, 2-ethylhexyl alcohol and sebacic acid in one stage, by reacting the glycol with the acid to form the glycol half-ester which is then reacted with the alcohol, and by reacting the alcohol with the acid and then reacting the half acid-ester formed with the triethylene glycol. Specifications 666,697 and 680,438 are referred to.  The Provisional Specification refers to the use of excess of the dialkyl ester in the reaction whereby there results a blend of complex ester and the excess of dialkyl ester.ALSO:Synthetic lubricants being complex esters of the general formula R1-OOC-R2-COO-R3-OOC-R4-COOR5 in which R1 and R5 are aliphatic alcohol or ether-alcohol residues, R2 and R4 are the hydrocarbon radicals of aliphatic dicarboxylic acids or are direct carbon-to-carbon linkages and R3 is the hydrocarbon or oxygenated hydrocarbon radical of a glycol or polyglycol, all the Rs being saturated, are prepared by heating together in proportions yielding the complex ester the appropriate di-ester of the alcohol and dicarboxylic acid with the glycol or polyglycol in the presence of an esterification catalyst and removing the alcohol of esterification formed.  The complex esters preferably contain 20 to 100 carbon atoms per molecule.  Suitable starting materials are C4 to C24 polyglycols, C1 to C12 alcohols, especially 2-ethyl hexanol and iso-octanol and C6 to C20 dicarboxylic acids especially adipic and sebacic acids, though acids down to oxalic may be used.  Experiments are described illustrating the production of complex esters from di-2-ethylhexyl sebacate and (1) triethylene glycol and (2) polyglycol 200 (predominantly tetraethylene glycol) by refluxing the reactants in the presence of p-toluene sulphonic acid and removing the alcohol of esterification as overhead and comparison is made with the methods of making the same triethylene glycol complex ester by reacting together triethylene glycol, sebacic acid and 2-ethyl hexyl alcohol in one stage, by reacting the glycol with the acid to form the glycol half-ester which is then reacted with the alcohol and by reacting the alcohol with the acid and then reacting the half acid-ester formed with the triethylene glycol.  Specifications 666,697 and 680,438 are referred to.  The Provisional Specification refers to the use of excess dialkyl ester in the reaction whereby there results a blend of complex ester and the excess of dialkyl ester.